Add plugin_fw.sh test for v2 and run as part of installer.

Add plugin_fw.sh test for v2 and run as part of installer.

To deploy to multiple clusters, set the KUD_PLUGIN_FW_CLUSTERS
environment variable to the following format (an array of cluster data
objects):

[
  {
    "metadata": {
      "name": "NAME",
      "description": "DESCRIPTION",
      "userData1": "USER_DATA_1",
      "userData2": "USER_DATA_2"
    },
    "file": "KUBECONFIG_PATH"
  },
  {
    ...
  }
]

Issue-ID: MULTICLOUD-1217
Signed-off-by: Todd Malsbary <todd.malsbary@intel.com>
Change-Id: I4c80fbcef1162b441c4dfba4ce2bfd3ac419bc25